How to shift a String in a rectangle which is type of Canvas

Hi,
I had create a rectangle in Canvas like the textfield and now I can print my input in that rectangle, I want that how can I write the input when it's size is bigger than the rectangle! I want that when it's size is bigger than the rectangle the remain of my input must be shown and the input which I wrote earlier must be shifted! actualy I want to scroll my input in the rctangle, How can I do it? Could anyone show me sample code for it please?to scrolling the input in the rectangle I worte some code like below but when i scroll the input with Canvas.Right the String which I inserted after scrolling will be seprated to characters! Could you help me to solve it please?How could I shift the String when I click on Canvas.Right?